A byte is the smallest addressable unit of storage in a computer system. If a single datum is larger than a byte, it will need to be stored in a sequence of bytes. The system of interpretation of this sequence of bytes is referred to as the byte order format.
Generally, there are multiple types of byte order formats. The most widely used byte order formats are Most Significant Byte First, commonly referred to as bigendian, and Least Significant Byte First, commonly referred to as littleendian. Typically, a particular system (e.g., a computer system) is configured to use a particular byte order format (e.g., bigendian or littleendian). In a bigendian system, the most significant byte of a multi-byte datum is stored at the lowest memory address, the next most significant byte of the data is stored at the next higher address, and so on. Conversely, in a littleendian system, the least significant byte of a multi-byte datum is stored at the lowest memory address, the next least significant byte of the data is stored at the next higher address, and so on. Attempts to design systems capable of using multiple byte order formats (e.g., systems that can use either of the bigendian and littleendian formats, so called bi-endian systems) have led to complicated implementations that reduce system performance.